1. Field of the Invention
The present invention relates to impact judgement technology for judging impacts between three-dimensional models and moving objects in an artificial three-dimensional space, as used in a video game device, for example.
2. Description of the Related Art
In recent years, a variety of game devices have become widely used for displaying characters moving in an artificial three-dimensional space on a monitor screen. In these game devices, games simulating car races, skiing, surfing, motor boats, snowboards, skateboards, and the like, are known.
Moreover, in games involving moving characters, immobile objects which do not perform movement, such as geographical features, including land surface, mountains, rivers, and the like, are also displayed in the artificial three-dimensional space. These geographical non-moving objects are constituted by three-dimensional models comprising a combined plurality of polygons having quadrilateral shapes.
The game is developed by moving the characters according to the operations of the player, within the space in which the non-moving objects are drawn. Moreover, if a character contacts a non-moving object during development of the game, this is represented in the game by generating a sound effect at that timing, or the like, thereby increasing interest in the game. Consequently, it is necessary to perform impact judgement to determine whether or not the character has made contact with a non-moving object.
On the other hand, in order to depict background images in a realistic manner, the non-moving objects, such as geographical features, and the like, within the space in which the character is moving are constituted by an extremely large number of polygons. Therefore, a large amount of time is needed to perform the aforementioned impact judgement, and hence it is difficult to execute impact judgement at the appropriate timing.
Therefore, the present invention was devised with the foregoing problem in view, an object thereof being to provide an impact judgement method and device, a computer-readable recording medium recording an impact judgement processing program, and a video game device, whereby impacts between a moving object moving in an artificial three-dimensional space and three-dimensional model constituted by a plurality of polygons can be performed rapidly and accurately.
In order to achieve the above object, according to the present invention, an impact judgement device for judging impacts between a moving object moving in an artificial three-dimensional space and a three-dimensional model constituted by a plurality of polygons, the impact judgement device comprises: model storing means for storing the vertex-coordinates of the respective polygons of said three-dimensional model, and impact judging means for performing impact judgement using the movement vector of said moving object and said vertex-coordinates; wherein said model storing means represents said vertex-coordinates by means of central-coordinates being an average value of the maximum value and minimum value of the each of the coordinate components, an expansion factor to be used for achieving prescribed value by multiplication by the difference between the maximum value and minimum value of each coordinate component, and converted vertex-coordinates obtained by subtracting said central-coordinates from the respective vertex-coordinates and then multiplying by said expansion factor; and stores said central-coordinates and said expansion factor in a floating-point value form, and said converted vertex-coordinates in an integer form.
According to the above described invention, vertex-coordinates which are conventionally stored as 32-bit floating point values, are expressed by central-coordinates, an expansion factor and converted vertex-coordinates, and since the converted vertex-coordinates are stored as 16-bit integer values, the memory capacity used to store the vertex-coordinates is reduced by approximately one-half, and impact judgement is performed rapidly.
These and other objects, features, and advantages of the present invention will become more apparent upon reading of the following detailed description along with the accompanied drawings.